4.6 NUETRAL POINT CLAMPED (NPC) INVERTERS


Known as three-level inverters

Problem of 2-level inverter in high-power applications
High DC page link voltage requires series connection of devices  difficulty in dynamic voltage sharing during switching

Solved using NPC inverter or multilevel inverter

NPC inverter circuit


NPC (3)

DC page link capacitor split to create neutral point 0

Q11, Q14 : main devices (2-level inverter)

Q12, Q13 : auxiliary devices – clamp output potential to ne ....etc

[:=Read Full Message Here=:]

PRESENTED By
SUDHAKAR AKKI


SPACE VECTOR MODULATION FOR TWO LEG INVERTERS
INTRODUCTION
• Semiconductor switches mainly determine the overall price of power converters.
• The main objective of this project is to prove 2leg inverters are the best option for low power applications for getting the good performance.
• Two leg inverter produces the square wave or quasi-square wave. but low power applications allow the two leg inverter output.
• In many industrial applications, it is often required to v ....etc

[:=Read Full Message Here=:]

Abstract-
A pulse skipping control strategy is proposed to improve efficiency of grid-tied inverters at light loads. To maximize the efficiency of pulse skipping operation mode, three key parameters are identified and optimized based on a loss model, which is developed to find the maximal efficiency points using a three-dimensional search technique. A 200W prototype inverter was setup to verify the proposed control strategy. The experimental results show that the proposed pulse skipping control strategy greatly impr ....etc

[:=Read Full Message Here=:]

1. Design and Implementation of Microcontroller based PWM technique for Sine wave Inverter
2. A novel DC-AC Single Phase Resonant Inverter using soft switching boost converter
3. Study on Dual-Loop Grid Current Control Scheme for Grid-Connected Inverter with an LCL-Filter
4. ZVS H-bridge Inverter using Soft Switching Boost Converter
5. A Novel Hybrid Modulation Scheme for an Isolated High-Frequency-Link Fuel Cell Inverter
6. ZVS Resonant DC-link Inverter using Soft Switching Boost Converter
7. Comparison of Z-Source Inverter and Traditi ....etc

[:=Read Full Message Here=:]

Abstract
In adjustable speed drive applications, the switching of the inverter semiconductors generates common
mode currents as well as harmful overvoltages on the motor terminals when long cables are used.
Consequently, bulky and expensive input and output filters must be used. This work aims at reducing
these disturbances from their origin by using a three-level neutral-point-clamped (NPC) inverter
controlled with a new pulse-width-modulation (PWM) strategy. Whereas previous common mode
noise-reducing strate ....etc

[:=Read Full Message Here=:]

Abstract
Multilevel inverter technology has emerged recently
as a very important alternative in the area of high-power
medium-voltage energy control. This paper presents the most
important topologies like diode-clamped inverter (neutral-point
clamped), capacitor-clamped (flying capacitor), and cascaded
multicell with separate dc sources. Emerging topologies like
asymmetric hybrid cells and soft-switched multilevel inverters are
also discussed. This paper also presents the most relevant control
and modulation methods developed f ....etc

[:=Read Full Message Here=:]

Introduction

An inverter is an electrical device that converts direct current (DC) to alternating current (AC); the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits.
Static inverters have no moving parts and are used in a wide range of applications, from small switching power supplies in computers, to large electric utility high-voltage direct current applications that transport bulk power. Inverters are co ....etc

[:=Read Full Message Here=:]

Abstract
A general pulsewidth modulation (PWM) method for control of four-switch three-phase inverters is presented. The proposed vector PWM offers a simple method to select three or four vectors that effectively synthesize the desired output voltage, even in presence of voltage oscillations across the two dc-link capacitors. The method utilizes the so called space vector modulation, and includes its scalar version. Different vector combinations are compared. The effect ofWye and delta motor winding connections over the pulse width mod ....etc

[:=Read Full Message Here=:]

name dinesh
mini projet report
Voltage source inverters (VSI) have been widely used in uninterruptible power supplies, unified power flow controllers or unified power quality conditioners, and distributed generation systems (DGS). VSIs are inherently efficient, compact, and economical devices used to control power flow and provide quality supply. VSIs can be classified as voltage-controlled VSIs (VCVSIs) and current-controlled VSIs (CCVSIs), depending on their control mechanism. In this paper, a detailed comparison of VCVSIs and CCVSIs for DG ....etc

[:=Read Full Message Here=:]

ABSTRACT
From the late 19th century through the middle of the 20th century, DC to AC power conversion were accomplished using rotary converters or motor – generator sets. In the early 20th century, vaccum tubes and gas filled tubes begin to be used as switches in inverters circuits. The most widely used type of tube was the thyratron.
The origins of electro mechanical inverters explain the source of the term i ....etc

[:=Read Full Message Here=:]